PROCESS FOR DECREASING CHLORINE CONTENT IN CHLORINATED HYDROCARBONS

Abstract: The chlorine or halide content in a chlorinated hydrocarbon or halogenated aromatic hydrocarbon in an environment which admits to the presence of air and moisture can be reduced by bringing the chlorinated hydrocarbon or halogenated aromatic hydrocarbon into contact with a reagent which comprises (i) a complex of a substantially nontoxic metal having at least two oxidation states and (ii) a reducing agent which reductively returns the complex from its second oxidation step to its first oxidation stage. A representative embodiment involves bis-( eta <5>-cyclopentadienyl)titanium dichloride and sodium tetrahydridoborate. Optionally, the reaction is conducted in the presence of an aliphatic or aromatic amine, optionally in the presence of an inert organic solvent.

Description: PROCESS FOR DECREASING CHLORINE CONTENT IN CHLORINATED HYDROCARBONS Background of the Invention This invention pertains to a process for decreasing the content of chlorine in chlorinated hydrocarbons, and for reducing aromatic halide content in haiogenated aromatic hydrocarbons. Various chlorinated hydrocarbons such as polychlori- nated biphenylε, tetrachloroethylene, trichloroethylene, 1,2,3-trichloropropane, polychlorinated naphthalene, chlo¬ rine containing fluorocarbons ("Freons") , polychlorinated cyclodieneε such as aldrin and dieldrin, polychlorinated bicycloal anes such as irex etc. , are recognized environ¬ mental contaminants. Numerous chemical, physical, and microbiological methods for eliminating these presently are under investigation. While microbiological techniques are useful in bioremediation of many contaminants, such tech¬ niques have not proven satisfactory for highly chlorinated, products such as those containing four or more chlorine atoms; see e.g., Hill et al . , Appl . Biochem. Biotechnol . , 20/21, 233 (1989) and Waid, "PCBs and the Environment, " Vol. II, 78, CRC Press, Boca Raton, Florida. Various chemical approaches have been investigated but again it appears the greater the number of chlorine atoms in a target contaminant, the more difficult the dechlorination. Moreover systems which appear to be useful in the controlled environment of the laboratory encounter unexpected difficul¬ ties when an attempt is made to adapt the system to the com¬ petitive and ambient environment where such highly chlori¬ nated products pose the greatest problem. Wilwerding, U.S. Patent No. 4,931,167, describes the degradation of polychlorinated biphenyls in a non-aqueous medium using anhydrous metal halides such as the chlorides and bromides of aluminum, titanium, tin, iron, etc. Imamura et al . , U.S. Patent No. 4,957,717, describe the disposal of organic compounds by burning them in contact with a catalyst of a composite oxides such as titanium-sili¬ con composite oxides and titaniuirt-silicon-zirconium compos- ite oxides. Anderson et al . , U.S. Patent No. 5,035,784, describe degradation of polychlorinated biphenyls by photocatalysiε by ultraviolet light utilizing porous titanium ceramic mem¬ branes. Meunier, J. Organometal . Che , 204 (1981), 345-346 describes the selective reduction of aromatic iodides with sodium borohydride activated by a catalytic amount of bis- (η 5-cyclopentadienyl)titanium dichloride or r ~-cyclopentadi- enyltitanium trichloride in dimethylformamide and in the presence of air. Aromatic chlorine atoms were not affected. Kozloski, J. Chromatogr . , 318 (1985) 211-219 describes partial catalytic dechlorination of polychlorinated biphenyls with sodium borohydride and nickel boride cata¬ lyst. Stojkovski et al . , J. Chem. Tech. Biotechnol . 1990. 51, 407-417, describe dechlorination of polychlorinated biphenyls and polychlorinated naphthalenes with nickel chlo¬ ride/sodium borohydride catalysts. In a companion paper, J. C ejn. Tech. Biotechnol . , 1991, 51, 419-431, Stojkovski et al . extend the use of this nickel chloride/sodium boro¬ hydride system to chlorinated cyclodiene and bicyclic insec¬ ticides. Bosin et al . , Tetrahedron Letters , 4699-4650 (1973) report on the reduction of aryl halides with a sodium boro- hydride-palladium system. Carfagna et al . , J. Mol . Cat . 57 (1989) 23-28, describe the use of magnesium hydride and various metal halideε in the reduction of aryl monohalides. Rolla, J. Org. Chem. , 46, 3909-3911 (1981) reports on the use of sodium borohydride to reduce a variety of haio¬ genated hydrocarbons using hexadecyltributylphosphonium bro- ide as a catalyst. Bergbreiter et al . , J. Org. Chem. , 54, 5138-5141 (1S39) describe the use of tin catalyst attached to soluble polyethylene and polystyrene for use in alkyl halide reduc¬ tions. Loubinoux et al . , Tetrahedron Letters , 3951-3954 (1977) report on the activation of sodium hydride by certain metal salts in the reduction of various organic halides. Tabaei et al., Tetrahedron Letters , 2727-2730 (1991) describe the use of polyethylene glycol or tetraethylene glycol in the metal catalyzed reduction of chlorinated hydrocarbons with sodium borohydride or sodium alkoxyboro- hydride. DETAILED DISCLOSURE The present invention involves a method for chemically reducing the overall chlorine or halide content in com¬ pounds, generally but not necessarily chlorinated hydrocar¬ bons or haiogenated aromatic hydrocarbons. The process is characterized by the ability to operate economically in a mixed ambient environment, notably in the presence of water and oxygen found in air. Although not so limited, it has particular value as a pretreatment to microbiological degra¬ dation of chlorinated hydrocarbons in that highly chlori¬ nated compounds which are resistant to bioremediation can be converted to compounds having a lower content of chlorine, thereby being more susceptible to microbiological degrada¬ tion. Broadly the process involves bringing the chlorinated hydrocarbon into contact with a dechlorination reagent of the type described herein. Heat can be applied to acceler¬ ate the reaction. By conducting the reaction in the pres- ence of an aliphatic or aromatic amine, the scope of the reaction can be expanded to other haiogenated compoundε and a greater degree of dehalogenation can be achieved. The dechlorination reagent contains two principal components. The first component of the dechlorination reagent is a metal complex having at least two oxidation stateε. In a first, lower oxidation εtate, the complex iε operable to transfer an electron to the chlorinated hydrocarbon and thereby reductively eliminate a chlorine atom from the chlorinated hydrocarbon. In transferring the electron, the complex assumes its second, higher oxidation state; i.e. , it is oxidized. The second component of the reagent is a reducing agent operable to reductively return the complex from its second oxidation step to its first oxidation stage; i . e. , to reduce the complex back to its original oxidation state. It will be appreciated that the net result of these two reactions iε the consumption of the second component and the regeneration of the first component. Consequently the first component effectively acts as a catalyst in the senεe that while it participateε in the reduction of chlorinated hydro¬ carbon, it is returned to its original oxidation state in which it can enter into a further reaction. Consequently the amount of the first component which must be introduced into the environment is relatively small. Moreover while these two components are referred to herein as a reagent or system in that they co-act, in use they can be introduced either in pre-formed combination or separately. It is critical to the process, however, that both com¬ ponents operate under the ambient conditions of the environ¬ ment and do so without causing further contamination. For example, complexes containing nickel may be technically effective aε the first component in reducing chlorinated hydrocarbon but are unsuitable because the nickel of the complex thuε introduced into the environment itself iε toxic. Similarly sodium hydride and lithium aluminum hydride in theory are effective as the second component but both react with water and thus are unsuitable, being unsta¬ ble in a mixed environment. The first component will contain a substantially non¬ toxic transition metal of Group 4 or 5 (IVa or Va) and will form a complex with multidentate and unidentate organic and inorganic ligands. Particularly preferred are titanium and zirconium compounds including benzoates, chlorideε, salen complexes, prophyrins, tris(pyrazoyl) borateε, poly(alkylamino) complexes, poly(alkylamino) chelates, poly(thioalkyl) complexes, poly(thioalkyl) chelates, and mixtures thereof. One highly effective subclass are the organometallic complexes of titanium and zirconium εuch aε jis-(T7 5 -cyclopentadienyl)titanium dichloride, biε- (η -cyclo- pentadienyl) zirconium dichloride, η -cyclopentadienyl- zirconium trichloride, and T7 5 -cyclopentadienyltitanium tri- chloride. Particularly useful in view of its currently relatively low cost and performance iε bis- (η -cyclo- pentadienyl)titanium dichloride, alεo known aε titanocene dichloride. The second component will be a hydridoborate, typically a polyhydridoborate, such as an alkali metal or ammonium salt of a tetrahydridoborate, thiocyanatotrihydridoborate, cyanotrihydridoborate, acyloxytridridoborate, octahydrido- trihydridoborate, trialkylhydridoborate, acetanilidotri- hydridoborate, trialkoxyhydridoborate, and metal chelates thereof. Particularly useful in view of its current rela¬ tively low cost and performance is sodium tetrahydrido- borate . In the abεence of the firεt component, the hydrido- borate may εhow some dechlorination properties but the rate iε far slower and the range of chlorinated compounds in which such dechlorination is seen is far more limited than when the metal complex is present. The amine which iε added can be any aliphatic amine such aε trimethylamine, triethylamine, dimethylethylamine, etc. , an aromatic amine such as N,N-dimethylaniline, N,N- dimethylnaphthylamine, etc. , or an aromatic or nonaromatic heterocyclic amine such as pyridine, 1-methylimidazole, quinoline, piperidine, etc. Although primary and secondary amines can be employed, preferably the amine is a tertiary amine. Generally a molar excess of the amine is employed. While other non-amine bases such as sodium methoxide appear to have a slight effect in accelerating the under¬ lying reaction, this is by no means aε dramatic aε that observed upon addition of an amine. The target polychlorinated hydrocarbons, particularly polychlorinated aromatic compounds, often present a complex mixture of cogeners. In the case of PCB's for example, the cogeners present can number in the hundreds. It thus is convenient to study the use of the preεent reagent with εub- εtantially pure chlorinated compoundε. Aε shown below, the usefulness of the reagent in reducing the chlorine content of pure compounds also is seen in mixtures of chlorinated compoundε. The haiogenated hydrocarbons on which the process iε operable include haiogenated aromatic, aliphatic, and olefinic compounds such as polychlorinated biphenyls (PCB'ε), tetrachloroethylene, trichloroethylene, 1,2,3- trichloropropane, and the like. Other functional groupε εuch aε oxo groupε (ketoneε, carboxylic acidε and eεterε) , amino groupε (including secondary and tertiary amino groupε) , nitro groups and the like also can be present in the compound or compoundε being treated. Such if εuch a groupε, if susceptible to reduction, may be reduced in the course of the process. Such products generally are equally or more amenable to bioremediation. It will be appreciated that upon removal of one chlor¬ ine atom from a given polychlorinated compound, a further chlorine atom can and will be removed from the product by repetition of the reaction and in fact typically starting with a highly chlorinated compound a series of different products, each having a fewer but different number of chlor¬ ine atoms per molecule, will be produced. For example, beginning with hexachlorobenzene, the first product will be pentachlorobenzene. The pentachlorobenzene thus formed in turn will be converted to 1,2,3,4-tetrachlorobenzene and 1,2,4,5-tetrachlorobenzene. 1,2,4,5-Tetrachlorobenzene pro¬ duces 1,2,4-trichlorobenzene. Since these reactions proceed concurrently, a plurality of products generally are formed but the net result of the process will be a reduction in the overall chlorine content of the chlorinated hydrocarbon. The reactive intermediate generated from the chlori¬ nated hydrocarbon can react with other organic materials preεent in the rection area. For example if the treatment of 1,2,4,5-tetrachlorobenzene iε conducted in the presence of dimethylformamide as a solvent, the products can include not only 1,2,4-trichlorobenzene but also N,N-dimethyl-2,4,5- trichloroaniline. Similarly, when the procesε iε conducted with 1,3,5-trichlorobenzene, both N,N-dimethyl-3,5-dichloro- aniline and 1,3-dichlorobenzene will be produced. Whether this involves a nucleophilic mechanism or free radical mech¬ anism is not known but the products so fcrmed are in any event more amenable to bioremediation by reason of the net reduction in the number of chlorine atoms. Moreover, the present reagent appears to operate effec¬ tively not only on highly chlorinated compounds and but also on compounds containing only a few chlorine atoms. The reaction to which an amine iε added can be con- ducted in a variety of inert organic solvents such aε diglyme, triglyme, jbis-(2-ethoxyethyl) ether, tetrahydro- furan, dimethylεulfoxide, dimethylformamide, ethylene glycol dimethyl ether and the like. Particularly preferred are etherε such as diglyme. The following examples will serve to further exemplify the present invention without being construed aε being a limitation thereof. The designations uεed herein for the metal complexeε uεed are aε follows: Metallic Complex Designation oxo(tetraphenylporphyrinato)titanium oxide A η -cyclopentadienyltitamum trichloride B (salen)titanium dichloride C titanium trichloride D ~ , . . . jbαs-(rj -cyclopentadienyl)titanium dichloride E titanium tetrapropoxide F oxobis(acetylacetonato)titanium G titanium boride H {tris[3,5-dimethylpyrazoyl]borate) titanium trichloride I bis- (η -cyclopentadienyl) zirconium dichloride J EXAMPLE 1 A. Without Catalyst A mixture of 2 mmol of hexachlorobenzene and 8 mmol of sodium tetrahydridoborate in 10 L of dimethylformamide was heated with stirring for 36 hours at 88°C in an air atmo¬ sphere in a reaction vessel equipped with a condenser. At the end of this time, water was added and the mixture extracted with ether. Analysis of the ethereal extract by gas chromatography (flame ionization detector) and by gas chromatography/masε spectrography indicated the following composition: Compound mmol tetrachlorobenzeneε 0.475 N,N-dimethyltetrachloroanilines 0.482 N,N-dimethyltrichloroanilines 0.363 trichlorooenzeneε 0.107 B. With Catalyst By following substantially the same procedure as that set forth in Part A with 1.87 mmol of hexachlorobenzene and 7.88 mmol of sodium tetrahydridoborate in 10 mL of dimethyl- formamide with heating at 85"C but adding 0.19 mmol of metal complex I, the following reaction composition was obtained after 11 hours. Compound mmol tetrachlorobenzenes 0.502 N,N-dimethyltetrachloroanilines 0.682 N,N-dimethyltrichloroanilineε 0.393 trichlorobenzeneε 0.069 EXAMPLE 2 Following the procedure of Example 1, Part B, 2 mmol of hexachlorobenzene, 8 mmol of sodium tetrahydridoborate, and 0.2 mmol of each of metal complexes A, B, C, D, and E were heated in 10 mL of dimethylformamide. The conditions and results are summarized on Table I. EXAMPLE 3 A. Without Catalyst A mixture of 2 mmol of pentachlorobenzene and 8 mmol of sodium tetrahydridoborate in 10 L of dimethylformamide was heated with εtirring for 1.1 hourε at 85"C in an air atmo- εphere in a reaction veεεel equipped with a condenεer. At the end of thiε time, water waε added and the mixture extracted with ether. Analysis of the ethereal extract by gas chromatography (flame ionization detector) and by gaε chromatography/masε spectrography indicated the following composition: Compound mmol pentachlorobenzene (starting compound) 1.086 1,2,4,5-tetrachlorobenzene 0.56 1,2,3,4-tetrachlorobenzene 0.063 B. With Catalyst By following substantially the same procedure as that set forth in Part A but adding 0.2 mmol of metal complex E, the following reaction composition was obtained after 1.1 hours. Compound mmol pentachlorobenzene (starting compound) 0.732 1,2,4,5-tetrachlorobenzene 0.566 1,2,3,4-tetrachlorobenzene 0.077 1,2,4-trichlorobenzenes 0.013 EXAMPLE 4 A. Without Catalyst A mixture of 1 mmol of 1,2,4,5-tetrachlorobenzene and 4 mmol of εodiu tetrahydridoborate in 10 L of dimethylfor - amide waε heated with stirring for 3.5 hours at 95°C in an air atmosphere in a reaction vessel equipped with a con¬ denser. The reaction mixture, extracted and analyzed as described above, had the following composition: Compound mmol 1,2,4,5-tetrachlorobenzene (starting compound) 0.84 1,2,4-trichlorobenzene 0.11 N,N-dimethyl-2,4,5-trichloroaniline 0.05 B. With Catalyst By following substantially the same procedure as that set forth in Part A but adding 0.2 mmol of metal complex E, the following reaction composition was obtained after 3.5 hours. Compound mmol 1,2,4,5-tetrachlorobenzene (starting compound) 0.12 trichlorobenzene 0.45 N,N-dimethyl-2,4,5-trichloroaniline 0.43 EXAMPLE 5 Following the procedure of Example 4, Part B, 1 mmol of 1,2,4,5-tetrachlorobenzene, 4 mmol of sodium tetrahydrido- borate, and the indicated amount of each of metal complexes E, F, G, H, and J were heated in dimethylformamide. The conditions and results are summarized on Table II. Table II Complex C 6 Cl 3 H 3 a C 6 Cl 3 H 2 N(CH 3 ) 2 1 C 6 Cl4H 2 (Recovered) mmol mmol mmol E 0.45 0.43 0.12 E 0.42 0.42 0.16 F 0.33 0.38 0.29 J 0.30 0.56 0.14 0.11 0.05 0.84 a = 1,2,4-trichlorobenzene b = N,N-dimethyl-2,4,5-trichloroaniline > I EXAMPLE 6 Following the procedure of Example 4, Part B, 2 mmol of 1,2,4,5-tetrachlorobenzene, 8 mmol of sodium tetrahydrido¬ borate, and the indicated amount of each of metal complexeε A, B, D, C, and I were heated in dimethylformamide. The conditions and resultε are summarized on Table III. Table III Complex C 6 Cl 3 H 3 a C 6 C1 3 H 2 N(CH 3 ) 2 b C6Cl4U 2 (Recovered) mmol mmol mmol Λ 0.06 0.06 1.88 B 0.56 1.24 0.20 C 0.48 1.26 0.26 D 0.48 1.36 0.16 I 0.48 1.30 0.22 a - 1,2,4-trichlorobenzene b = N,N-dimethyl-2,4, 5-trichloroaniline Ul EXAMPLE 7 A. Without Catalyst A mixture of 8 mmol of sodium tetrahydridoborate and 2 mmol of 1,4-dichlorobenzene in 10 L of dimethylformamide waε heated with stirring for 6.5 hourε at 80"C in an air atmosphere in a reaction vessel equipped with a condenser. Upon extraction and analysis as described above, only start- ing material could be detected. B. With Catalyst By following substantially the same procedure as that set forth in Part A but adding 0.2 mmol of metal complex E, the following reaction composition was obtained after 6.5 hours. Compound mmol 1,4-dichlorobenzene (starting compound) 1.96 chlorobenzene 0.04 EXAMPLE 8 1,2,3-Trichloropropane was treated with sodium tetra¬ hydridoborate and metal complex E at 100"C for 1 hour in subεtantially the faεhion deεcribed above. Gaε chro atogra- phy/mass spectrography indicated no 1,2, 3-trichloropropane remained in the reaction mixture. EXAMPLE 9 Treating tetrachloroethylene (325 mg) with sodium tetrahydridoborate and metal complex E at 93"C for 3 hourε and 20 min. in subεtantially the faεhion deεcribed above converted 98% of εtarting material to trimethylamine, 1,1- dichloroethylene, 1,2-dichloroethylene, and N,N-dimethyl- aminomethanol as determined by gas chromatography/masε spec- trography. EXAMPLE 10 Five and one-half parts by weight of a commercial mix¬ ture of polychlorinated biphenyls (Aroclor 1248) were extracted with ether and the ether then evaporated in vacuo . To the residue were added 45 partε by weight of εodium tetrahydridoborate, 25 partε by weight of metal complex E, and 1 part by volume of dimethylformamide. The mixture waε heated at 92°C. After one hour the mixture became viεcouε and an additional 0.5 part by volume of dimethylformamide waε added. After an additional 17 hours of heating (a total of 18 hours) , the reaction products were extracted with ether and passed through a short column of silica gel to remove the residual metal complex. Upon analysis, the reac- tion product contained about 25% (1.36 parts by weight) of polychlorinated biphenyls, indicating a 75% reduction. The results of utilization of the foregoing procedure with metal catalystε A, B, C, D, E, H, I, and J are shown on Table IV. Temp. lorination • C 100 100 100 100 100 92 100 92 EXAMPLE 11 A commercial mixture of polychlorinated biphenylε (Aroclor 1248, 3.3 partε by weight) waε extracted with ether and the ether then evaporated in vacua . To the reεidue were added 21 partε by weight of j is-(r? 5 -cyclopentadienyl)- titaniu tetrahydridoborate and 1 part by volume of dimeth- ylformamide. The mixture was heated at 100"C. After a total of 18 hourε, the reaction products were extracted with ether and passed through a short column of silica gel to remove the residual metal complex. Upon analyεiε, the reac¬ tion product contained about 40% (1.31 partε by weight) of polychlorinated biphenylε, indicating a 60% dechlorination. The foregoing example demonstrates that the metal complex and the hydridoborate can be combined in the same molecule to achieve the desired result, requiring however a stoichiometric amount of the reagent. Although this con- firmε the working premise of the invention, it introduces metal in excess of that which is required in order to effec¬ tively lower chlorine content with hydridoborate and a catalytic amount of the metal complex. EXAMPLE 12 A mixture of 0.3 mmol of metal complex E and 30.0 mmol of sodium tetrahydridoborate in 30 mL of dimethylformamide waε heated with stirring for 1 hour at 92°C in an air atmo- sphere in a reaction vessel equipped with a condenser. The reaction product was filtered through a Celite plug and a fine glass frit to produce the dehalogenation reagent as a dark brown εolution. If 1,2,4,5-tetrachlorobenzene iε added to thiε εolution and the mixture then heating at 92"C, it iε reduced to a level below 10% in about 60-65 minuteε with the formation of 1, 2,4-trichlorobenzene and N,N-dimethyl-2,4 , 5-trichloro- aniline (as determined by gas chromatography/masε spectro¬ graphy) . EXAMPLE 13 A reaction vessel equipped with a condenser iε charged with approximately 5 g of soil contaminated with poly¬ chlorinated biphenyls. A portion of sodium tetrahydrido¬ borate, and 150 mg of metal complex E in dimethylformamide are added and the mixture is heated with stirring at 100"C in an air atmosphere in a reaction vessel. After 30 minutes, additional sodium tetrahydridoborate and metal com¬ plex E are added. (Any material on the walls of the vessel can be washed off with dimethylformamide. ) After another 20 minutes, additional sodium tetrahydridoborate is added and the reaction mixture is stirred for 18 hours. The reaction can be quenched with water and the reaction mixture exhaus¬ tively extracted with ether (to insure partition of all chlorinated biphenyls) . Analysiε of the ethereal extractε iε performed by gas chromatograph and compared against the untreated contaminated soils. The resultε of utilization of the foregoing procedure with samples of soil contaminated with polychlorinated biphenyls produced are shown on Table V. Soil Sample I II III I Approximately 2 to 5 g of the soil sample are placed into a 20 mL serum vial, the sample iε amended with an equal volume mL/g of distilled water and to this mixture are added 10 mL of diethyl ether. The vial is sealed and shaken on a rotary shaker for 24 hours. The ether phase then iε tranε- ferred to a 1.5 mL serum vial for analysis. (If needed, the original ether extract can be either concentrated or diluted to ensure accurate sample analysis.) Samples containing interfering εubεtanceε are cleaned uεing appropriate methodε. Non-PCB oilε (hydraulic fluidε, mineral oil, etc. ) are removed by passing the extractε through a conditioned magnesium silicate matrix. The retained PCBs are eluted from the matrix with hexane and the wash iε either diluted or concentrated for GC analysis. Samples which are found to contain elemental sulfur are cleaned by combining 2 L of the sample extract with 1 mL of reagent containing 3.39 g of tetrabutylammonium hydrogen sulfate and 25 g sodium sulfite in 100 mL of water and 1 L of 2-propanol. After mixing for five minutes, an additional 3 L of water are added to remove the alcohol and reagent. The ethereal layer is transferred to a gas chromatograph equipped with an electron capture detector (300"C) , a split/splitless capillary injector (300"C) , and a fused silica column (length = 30m, inner diameter = 0.25 mm) coated with a 0.25 μm bonded liquid phase of polydimethyl- εiloxane. The column iε temperature programmed from 160'C to 200°C at 2°C/min/no hold time to 240°C at 8°C/min and held for 10 minuteε. The gas flow rates are set as follows: carrier gaε (helium) at 23 cm/εec (067 mL/ in) ; make-up gaε (nitrogen) at 33 mL/min; and a split ratio of 16. Chromatograms of the samples are integrated on a peak- by-peak basiε and the area of each peak iε normalized with respect to standard mixtures of known PCB compoεition. Figure 1 iε a gas chromatrogra of soil before treat- ment from which Samples I and II were taken. The plotting attenuation iε 40. The retention time is a function of the degree of chlorination. Figures 1A and IB are gaε chromatogramε of Sa pleε I and II, reεpectively, after dechlorination aε deεcribed above. The plotting attenuation for Figure 1A iε 21; that for Figure IB iε 31. In addition to an overall decrease in chlorine content in both sampleε, it will be observed that the population of heavily chlorinated componentε (a retention time of about 30 minutes or more) has been greatly reduced, the heavily chlorinated products having been converted to more lightly chlorinated products. Figure 2 is a gas chromatogram of Sample III before treatment. The plotting attenuation is 56. Figure 2A is the chromatrogram (plotting attenuation of 11) after dechlorination as described above. Again a shift in popula¬ tion from highly chlorinated compounds (retention time above about 30 minutes) to more lightly chlorinated compounds accompanies a reduction in overall chlorine content. EXAMPLE 14 A flask equipped with a magnetic stir bar and a water cooled condenser with an oil bubbler was charged with sodium tetrahydridoborate (568 mg, 15.0 mmol), J is-(^-cyclopenta¬ dienyl)titanium dichloride (374 mg, 1.5 mmol), Aroclor ® 1248 (1095 mg, 3.75 mmol based on an average molecular formula: C 12 H 6 **U) / and N,N-dimethylacetamide (DMA; 15.0 mL) . The flask was heated at 75"C for 10 hours and at 105°C for 4.25 hours. The reaction mixture was quenched with water (30 mL) and extracted with ethyl acetate (50 L) . The ethyl acetate solution was filtered through a short column of silica gel and washed with ethyl acetate. The resulting filtrate was analyzed by GC and compared with standard Aroclor ® 1248. Substantial reduction to mono-, di-, and trichloro PCBs was noted. No PCB containing more than three chlorine atoms per congener as present. EXAMPLE 15 A flask equipped with a magnetic stir bar and a water cooled condenser with an oil bubbler waε charged with 1,2,4 ,5-tetrachlorobenzene (648 mg, 3.0 mmol), sodium tetra- hydridoborate (1135 mg, 30.0 mmol), j is-(rj 5 -cyclopenta- dienyl)titanium dichloride (75 mg, 0.3 mmol), and 1-methyl- 2-pyrrolidine (NMP; 30.0 mL) . The reaction mixture was heated at 96°C in an oil bath. After 4.25 hours, lithium chloride (1.09 g, 30.0 mmol) was added. Aliquots were with- drawn by syringe, quenched with water, and extracted with diethyl ether. The ether layer was analyzed with the results shown in the following table. Only trichlorobenzene was produced. * lithium chloride added EXAMPLE 16 A flask equipped with a magnetic stir bar and a water cooled condenser with an oil bubbler was charged with 1,2,4,5-tetrachlorobenzene (648 mg, 3.0 mmol), sodium tetra¬ hydridoborate (1135 mg, 30.0 mmol), £>is-(^-cyclopenta¬ dienyl)titanium dichloride (75 mg, 0.3 mmol), and dimethyl- sulfoxide (30.0 mL) . The reaction mixture was heated at 92°C in an oil bath. Aliquotε were withdrawn by εyringe, quenched with water, and extracted with diethyl ether. The ether layer waε analyzed with the resultε shown in the following table. Only trichlorobenzene was produced. EXAMPLE 17 A flask equipped with a magnetic stir bar and a water cooled condenser with an oil bubbler was charged with 1,2,4,5-tetrachlorobenzene (648 mg, 3.0 mmol), sodium tetra¬ hydridoborate (1135 mg, 30.0 mmol), Jis-(^-cyclopenta¬ dienyl)titanium dichloride (75 mg, 0.3 mmol), and N,N- dimethylacetamide (30.0 L) . The reaction mixture waε heated at 95"C in an oil bath. Aliquots were withdrawn by syringe, quenched with water, and extracted with diethyl ether. The ether layer waε analyzed with the results shown in the following table. Only trichlorobenzene was produced and <1% of N,N-dimethyl-2,4,5-trichloroaniline were detected. EXAMPLE 18 The formation of gaε (mostly trimethylamine) in the chemical dechlorination procesε competeε with the reaction between the reagent and the targeted chlorinated hydrocar¬ bonε. In order to maximize the reaction of the reagent with the chlorinated hydrocarbonε, and to minimize the formation of gaε, a sequential addition procedure can be used to main¬ tain relatively low concentrations of sodium tetrahydrido¬ borate in the system. A reaction vessel was charged with chlorinated hydro¬ carbons (Aroclor ® 1248) , a magnetic stir bar, sodium tetra¬ hydridoborate (0.5 g) , ibis-(r? 5 -cyclopentadienyl)titanium dichloride (80 mg) , and N,N-dimethylformamide (30.0 mL) . The bottle was isolated by an oil bubbler and was heated to 95°C. After 1.5 hours, additional εodium tetrahydridoborate (0.5 g) waε added. Gaε evolution waε observed immediately. After an additional two hours, 0.5 g of sodium tetrahydrido¬ borate was added. Two more additions of εodium tetrahydri- doborate (0.5 g) were conducted within 1.5 hourε, and the reaction mixture waε further heated for 20 minutes. The total amount of sodium tetrahydridoborate added to the reac¬ tion mixture waε 2.5 g, and the reaction waε heated at 95°C for 5 hourε and 20 minutes. The reaction mixture waε quenched with 25 L of water and extracted with ethyl acetate (25 mL) . The ethyl acetate layer waε collected, dried over sodium carbonate, filtered through a short column of silica gel and washed with ethyl acetate. GC analysis waε conducted and the efficiency of dechlorination waε higher than in the case of one-time addition of sodium tetrahydridoborate. EXAMPLE 19 The reducing agent was prepared as in Example 12. (a) Reduction of PCB at 25iC A 20 L vial equipped with a magnetic stir bar was charged with Aroclor ® 1248 (12.8 mg) and the ex situ prepared reducing agent (10 mL, 10.0 mmol). Reduction proceeded slowly at 25 ,, C. (b) Reduction of Tetrachloroethylene A flask equipped with a magnetic stir bar and 30 mL of the ex situ prepared reducing reagent (30 mmol) waε charged with tetrachloroethylene (0.452 mg, 3.0 mmol), 1-chloro- octane (0.441 g) , and nonane (0.44 g) . The reaction mixture was held at 25°C for 40 hourε, after which time analysiε showed no tetrachloroethylene and only a small amount of chlorooctane remaining. (c) Reduction of 1 , 2 , 3-Tr ichlor opropane A flask equipped with a magnetic stir bar and 1,2,3- trichlorop opane-contaminated sand (20 g sand; 0.5 g trichloropropane and 0.67 g decane aε an internal analysis standard) and the ex situ prepared reducing reagent (30 mL; 30 mmol). The mixture was heated at 52°C for 3 hourε; more than 95% 1,2,3-trichloropropane waε reduced. (d) Reduction of 1,2, 3-Tetrachlorobenzene A mixture of the ex situ prepared reducing reagent (40 L; 64 mmol) and 1,2,4,5-tetrachlorobenzene (4.0 mmol) waε held at 25°C for two weekε. More than 70% of the tetra- chlorobenzene was reduced. EXAMPLE 20 A flask equipped with a magnetic stir bar waε charged with _bis-(rj 5 -cyclopentadienyl)titanium dichloride (55 mg, 0.22 mmol), sodium tetrahydridoborate (1230 mg, 32.5 mmol), 1,2,4,5-tetrachlorobenzene (0.449 g, 2.1 mmol), dimethyl- formamide (20.0 mL) and water (0.1 mL, corresponding to 1% water in the reaction mixture) . The reaction was heated at 85 β C with the rate of reduction being shown in the following table. Mole Fraction C 4 C1 4 0.990 0.990 0.970 0.900 0.600 0.001 Mole Fraction C 4 C1 4 0 . 900 0 . 860 0 . 820 0 . 780 0 . 020 EXAMPLE 21 Titanocene dichloride (171 mg, 0.69 mmol), sodium tetrahydridoborate (622 mg, 16.4 mmol) and octachloro- dibenzo-p-dioxin (195 mg, 0.39 mmol, 3.14 mmol C-Cl) were combined under a nitrogen atmosphere. Jbis-(2-Methoxyethyl) ether (20 ml) and pyridine (1.35 ml, 16.7 mmol) were injected under a nitrogen atmosphere. The reaction mixture then waε heated at 125°C under a nitrogen atmosphere. The reaction waε stopped after 3.5 hourε by addition of water and the reaction mixture extracted by toluene. The toluene layer waε purified by a εhort column of εilica gel and ana¬ lyzed by gaε chromotography (GC) . Octachlorodibenzo-p- dioxin waε completely converted to dibenzo-p-dioxin, the only product detected by GC. EXAMPLE 22 Titanocene dichloride (125 mg, 0.5 mmol), εodium tetrahydridoborate (454 mg, 12.0 mmol), and 4-bromobiphenyl (2.33 g, 10.0 mmol) were combined in a reaction veεsel under a nitrogen atmosphere. bis-(2-Methoxyethyl) ether (20 ml) and pyridine (1.0 ml, 12.4 mmol) were injected under a nitrogen atmosphere. The reaction mixture was heated at 125 β C under a nitrogen atmosphere. An aliguot (about 1.0 . I) was withdrawn by a syringe and quenched with water, and then the reaction mixture waε ex..acted by diethyl ether. The ether layer waε purified on a εhort column of εilica gel and analyzed by gaε chromotography/mass spectrometry (GC/MS) . 4-Bromobiphenyl was completely reduced to biphenyl with a pseudo-first order rate constant, k = 0.94 h -1 . EXAMPLE 23 Titanocene dichloride (125 mg, 0.50 mmol), sodium tetrahydridoborate (180 mg, 4.76 mmol), and decabromo- biphenyl (300 mg, 0.318 mmol, 3.18 mmol C-Br) in a reaction vessel under a nitrogen atmosphere. Jbis-(2-Methoxyethyl) ether (10.0 ml) and pyridine (0.385 ml, 4.76 mmol) were injected under a nitrogen atmosphere and the reaction ix- ture then heated at 125"C under a nitrogen atmosphere. The reaction was stopped after 24 hours by addition of water, and the reaction mixture extracted by toluene. The toluene layer waε purified on a short column of silica gel and ana¬ lyzed by GC/MS. Quantitative analysis (by addition of tridecane as an internal standard) indicated biphenyl was the major reaction product. EXAMPLE 24 Titanocene dichloride (75 mg, 0.30 mmol), sodium tetra¬ hydridoborate (80 mg, 2.11 mmol), and 2,4,6-trichloro-p- terphenyl (15 mg, 0.045 mmol, 0.135 mmol C-Cl) were combined under a nitrogen atmosphere. bis-(2-Methoxyethy1) ether (5.0 ml) and pyridine (0.17 ml, 2.10 mmol) were injected under a nitrogen atmosphere. The reaction mixture was heated at 125°C under a nitrogen atmosphere and the reaction then stopped after 16 hours by addition of water. The reac¬ tion mixture was extracted by toluene and the toluene layer purified on a short column of silica gel. Upon analysiε by GC/MS, the starting material, 2,4,6-trichloro-p-terphenyl, was found to be completely converted to p-terphenyl, the only product detected by GC/MS. EXAMPLE 25 Titanocene dichloride (75 mg, 0.30 mmol), sodium tetra¬ hydridoborate (80 mg, 2.11 mmol), and 1,2,3,4,-tetrachloro- naphthalene (50 mg, 0.19 mmol, 0.75 mmol C-Cl) were combined in a reaction vessel under a nitrogen atmosphere. Jbis-(2- Methoxyethyl) ether (5.0 ml) and pyridine (0.17 ml, 2.10 mmol) were injected under a nitrogen atmosphere. The reac¬ tion mixture was heated at 125°C under a nitrogen atmosphere and stopped after 18 hours by addition of water. The reac- tion mixture was extracted by toluene and the toluene layer purified on a short column of silica gel. Upon analysis by GC/MS, 1,2,3,4-tetrachloronaphthalene waε found to be completely reduced to naphthalene, the only product detected by GC/MS. EXAMPLE 26 A reaction vessel waε charged with titanocene dichlo¬ ride (75 mg, 0.30 mmol), εodium tetrahydridoborate (80 mg, 2.11 mmol) and octachlorodibenzofuran (30 mg, 0.068 mmol, 0.54 mmol C-Cl) under a nitrogen atmosphere. Jbi_s-(2-Meth- oxyethyl) ether (5.0 ml) and pyridine (0.17 ml, 2.10 mmol) were injected under a nitrogen atmosphere. The reaction mixture was heated at 125"C under a nitrogen atmosphere. The reaction was stopped after 16 hours by addition of water and then the reaction mixture extracted by toluene. The toluene layer was purified by a short column of silica gel and analyzed by GC/MS, which demonstrated that octachlorodi¬ benzofuran was completely reduced to dibenzofuran. EXAMPLE 27 A flask was charged with sodium tetrahydridoborate (200 mg, 5.29 mmol) and pentachlorophenol (381 mg, 1.43 mmol) in a dry box under a nitrogen atmosphere. Jbis-(2-Methoxyethyl) ether (10.0 ml) was injected into the flask and the reaction mixture was allowed to stand at 25 C° for 20 min. A solu¬ tion of titanocene dichloride (125 mg, 0.5 mmol), sodium tetrahydridoborate (254, 6.71 mmol) and pyridine (1.0 ml, 12.4 mmol) in Jbis-(2-methoxyethyl) ether (10 ml) then was added and the reaction mixture waε heated at 125'C under a nitrogen atmoεphere for 4 hours. The reaction mixture waε acidified by dilute hydrochloric acid and extracted by diethyl ether. GC/MS analysiε εhowed pentachlorophenol had been reduced to a mixture of moεtly monochlorophenol and some chlorobenzene. EXAMPLE 28 A flask waε charged with titanocene dichloride (125 mg, 0.5 mmol), sodium tetrahydridoborate (454 mg, 12.0 mmol) and 1,4-dichlorobenzene (1.47 g, 10.0 mmol) in a dry box under a nitrogen atmosphere. To the above flask, J is-(2-methoxy- ethyl) ether (20.0 ml) and pyridine (1.0 ml, 12.4 mmol) were injected under a nitrogen atmosphere. An ~ liquot (about 1.0 ml) waε withdrawn by a syringe and was quenched with water, and then waε extracted by diethyl ether. The ether layer waε purified by a short column of silica gel and waε analyzed by GC and GC/MS. Dichlorobenzene was converted to chlorobenzene with a pseudo-first order rate constant, k = 0.20 h "1 . Reduction reactions were run using 4-bromochlorobenzene (0.5M), sodium tetrahydridoborate (0.6 M) , amine (0.6 M) and titanium catalyst (0.025 M) in Jbis-(2-methoxyethyl) ether at 125"C. The effect of using various amines or mixtures of variouε amineε on rateε for 4-bromochlorobenzene reduction to chlorobenzene are (amine added, rate [kobgh -1 ] ) : pyri- dine, 1.01; 2-picoline, 0.67; 2,6-lutidine, 0.03; 3,5-luti- dine, 0.84; N,N-dimethyloctylamine, 0.06; N,N-dimethyloct- ylamine (0.3 M) pluε pyridine (0.3 M), 1.4. These data show that sterically uncrowded pyridines are more effective promoters of the reduction reaction than are simple aliphatic amines, but that a mixture of an aliphatic amine and a pyridine iε especially good. Reduction rates for other bromobenzenes under similar conditions (pyridine, 0.6 M) are: 4-bromobiphenyl, 1.11; p-dichlorobenzene, 0.20; 4- chlorobiphenyl, 0.22. EXAMPLE 29 Titanocene dichloride (175 mg, 0.70 mmol), sodium tetrahydridoborate (533 mg, 14.0 mmol) and 1,1,1-trichloro- 2,2-bis-(4-chlorophenyl)ethane (500 mg, 1.41 mmol, 7.05 mmol C-Cl) were mixed under a nitrogen atmosphere and Jbis-(2- methoxyethyl) ether (10 ml), pyridine (0.57 ml, 7.05 mmol) and N,N-dimethyloctylamine (1.44 ml, 7.00 mmol) were injected under a nitrogen atmosphere. The reaction mixture waε heated at 125*C. An aliquot (about 1.0 ml) waε with- drawn, quenched with water, and extracted with ethyl acetate. The ethyl acetate layer waε purified though a short column of silica gel and analyzed by GC/MS. The starting material 1,1, l-trichloro-2,2 -bis-(4-chlorophenyl)- ethane was completely reduced in 20 minutes, and l,l-Jis-(4- chlorophenyl)ethane (40%), 1-phenyl,l-(4-chlorophenyl)ethane (50%) and 1,1-biphenylethane (10%) were obtained. After further heating at 125°C for 1.67 hours (total 2 hours), l,l-J is-(4-chlorophenyl)ethane (1%), l-phenyl-l-(4-chloro- phenyl)ethane (32%) and 1,1-biphenylethane (67%) were found to be present. Only 1,1-biphenylethane was present after further heating at 125°C for 2 hours (total 4 hours). EXAMPLE 30 Titanocene dichloride (125 mg, 0.50 mmol) and sodium tetrahydridoborate (378 mg, 10.0 mmol) were mixed under a nitrogen atmosphere and jis-(2-methoxyethyl) ether (8.0 ml), pyridine (0.8 ml, 10.0 mmol), and tetrachloroethylene (0.2 ml, 8.00 mmol C-Cl) were injected under a nitrogen atmo¬ sphere. The reaction flask was sealed, and the reaction mixture was heated to 55"C with the vapor phase being sam- pled periodically. GC/MS analysis showed tetrachloroethyl¬ ene was completely reduced to trichloroethylene and dichloroethylene (three isomerε) in 20 hourε. EXAMPLE 31 High "organic content" garden soil (10.2 gm) was heated at 90°C to remove superficial water and was then spiked with Aroclor ® 1248 (1.05 gm, 14.8 mmol C-Cl, 9.3% PCB by weight). The soil sample was suspended in 20 ml of bis- {2- methoxyethyl) ether and heated at 125°C with titanocene dichloride (171 mg, 0.687 mmol, 0.05 equiv. per Cl) , sodium tetrahydridoborate (822 mg, 21.7 mmol, 1.47 equiv. per Cl) , pyridine (0.68 ml, 8.4 mmol, 0.57 equiv. per Cl) and N,N- dimethyloctylamine (1.73 ml, 8.4 mmol, 0.57 equiv. per Cl) . A mixture containing about 50% biphenyl and about 50% 3- chlorobiphenyl waε obtained after 24 hourε of treatment. By increasing the amount of reducing agent to a level sufficient to consume any residual moisture, the foregoing procedure can be used similarly on soil which has not been pre-dried. Hence while moisture reduces efficiency (by requiring more reducing agent) , moisture is not a poison to the activity of the transition metal complex catalyst. EXAMPLE 32 A freshly dried and spiked soil sample (10.2 gm soil, 1.02 gm Aroclor ® 1248, 14.4 mmol C-Cl, 9.1% PCB by weight) was heated at 125 β C in 20 ml of Jbis-(2-methoxyethyl) ether in the presence of titanocene dichloride (366 mg, 1.47 mmol, 0.10 equiv. per Cl) , sodium tetrahydridoborate (1.335 g, 35.28 mmol, 2.4 equiv. per Cl) , pyridine (1.43 ml, 17.7 mmol, 1.2 equiv. per Cl) and N,N-dimethyloctylamine (3.63 ml, 17.7 mmol, 1.2 equiv. per Cl) . After 12 minutes, a mix¬ ture consisting only of dichlorobiphenylε (about 70%) and monochlorobiphenylε (about 30%) waε obtained. After further heating for a total of 2 hourε, only biphenyl waε obεerved. EXAMPLE 33 A reaction vessel is charged with 171 mg (0.687 mmol) of titanocene dichloride and 622 mg (16.4 mmol) of sodium tetrahydridoborate under a nitrogen atmosphere. A solution of 1000 mg of Aroclor 1248, a polychlorinated biphenyl (3.43 mmol, based on an average MW 292, assuming 13.7 mmol of C-Cl functional groups), and 1.35 ml of pyridine (16.7 mmol) in 20 mL of Jbis-(2-methoxyethyl) ether is added. The reaction mixture is heated at 125°C. One milliliter aliquots are withdrawn periodically, quenched with water, extracted with ethyl acetate, purified by passing through a short column of silica gel, and analyzed by gaε chromatography. Significant dechlorination iε obεerved after 3.5 hourε with total dechlorination to biphenyl after 8.4 hourε. (cont'd next page) * = b phenyl EXAMPLE 34 One hundred forty milligramε of titanocene dichloride (0.56 mmol), 378 mg of sodium tetrahydridoborate (10.0 mmol) and 190 mg of 4-bromochlorobenzene (1.0 mmol) are introduced into a reaction vessel under a nitrogen atmosphere and 10 L of bis-(2-methoxyethyl) ether are added. The reaction mixture is heated at 50 ° C and 1 mL aliquotε are withdrawn periodically, quenched with water, extracted with diethyl ether, purified by passing through a short column of silica gel, and analyzed by gas chromatography. TABLE 34 A Time (mole fraction) (hours) 4-Bromochlorobenzene Chlorobv.nzene 0. 00 1. 00 0. * 0 9 . 17 1. 00 0.00 After 9.2 hours, 41.2 of dimethylethylamine (0.56 mmol) are added and the reaction allowed to continue. TABLE 34B Time (mole fraction) (hours) 4-Bromochlorobenzene Chlorobenzene 9.66 0.89 0.11 10.23 0.84 0.16 11.08 0.81 0.19 After 11.15 hours at 50"C, an additional 169 mg of dimethylethylamine (2.31 mmol) are added and the reaction allowed to continue. TABLE 34C Time (mole fraction) (hours) 4-Bromochlorobenzene Chlorobenzene 13.40 0.70 0.30 13.75 0.47 0.53 14.28 0.23 0.77 14.97 0.09 0.91 15.85 0.00 1.00 EXAMPLE 35 One hundred twenty-five milligrams of titanocene dichloride (0.5 mmol), 454 mg of sodium tetrahydridoborate (12.0 mmol) and 1900 mg of 4-bromochlorobenzene (10.0 mmol) are introduced into a reaction vessel under a nitrogen atmo¬ sphere. Ten milliliters of j is-(2-methoxyethyl) ether and 1.65 L of triethylamine (11.8 mmol) are added. The reac¬ tion mixture iε heated at 73"C and 1 mL aliquotε are with¬ drawn periodically, quenched with water, extracted with diethyl ether, purified by passing through a short column of silica gel, and analyzed by gas chromatography. Reduction of 4-bromochlorobenzene iε obεerved with a rate of k ODS = 2.36 x 10~ 2 (h _1 ) . The reaction iε quenched after 93.6% conversion. TABLE 35 (mole fraction) 4-Bromochlorobenzene Chlorobenzene 1.00 0.00 0.761 0.239 0.393 0.607 0.301 0.699 0.227 0.773 0.123 0.877 0.064 0.936 EXAMPLE 36 One hundred twenty-five milligrams of titanocene dichloride (0.5 mmol), 378 mg of sodium tetrahydridoborate (10.0 mmol), 27 mg of sodium methoxide (0.5 mmol), and 190 mg of 4-bromochlorobenzene (1.0 mmol) are introduced into a reaction vessel under a nitrogen atmosphere and 10 L of ibis-(2-methoxyethyl) ether are added. The reaction mixture is heated at 50"C and 1 L aliquots are withdrawn periodi¬ cally, quenched with water, extracted with diethyl ether, purified by passing through a short column of silica gel, and analyzed by gas chromatography. TABLE 36A Time (mole fraction) (hours) 4-Bromochlorobenzene Chlorobenzene 0.067 0.977 0.023 0.442 0.976 0.024 1. .3 0.965 0.035 3.-57 0.837 0.163 After 3.75 hours, 416 mg of dimethylethylamine (5.69 mmol) are added and the reaction allowed to continue. The following results are obtained. TABLE 36B Time (mole fraction) (hours) 4-Bromochlorobenzene Chlorobenzene 4.117 0.578 0.422 4.617 0.383 0.617 5.183 0.207 0.793 6.300 0.068 0.932 11.167 0.000 1.000

Claims: WHAT IS CLAIMED IS: 1. In the process of reducing halide content in haiogenated aromatic hydrocarbons by reduction in the presence of a reagent comprising (i) at least one complex of a transi- tion metal of group 4 or 5 with a multidentate or uniden- tate organic or inorganic ligand and (ii ) a reducing agent, the improvement which comprises conducting the reduction in the presence of an aliphatic or aromatic amine and an inert organic solvent. 2. The process according to claim 1 wherein the haiogenated aromatic hydrocarbons are polychlorinated aromatic hydro- carbons. 3. The process according to claim 2 wherein the polychlori- nated aromatic hydrocarbons are polychlorinated biphenyls. 4. The process according to claim 1 wherein the amine is trimethylamine, triethylamine, dimethylethylamine, N,N- dimethylaniline, N,N-dimethylnaphthylamine, pyridine, 1- methylimidazole, quinoline, or piperidine. 5. The process according to claim 4 wherein the amine is triethylamine, dimethylethylamine, or pyridine. 6. The process according to claim 1 wherein the inert organic solvent is diglyme, triglyme, Jbis-(2-ethoxyethyl) ether, tetrahydrofuran, dimethylsulfoxide, dimethyl- formamide, or ethylene glycol dimethyl ether. 7. The process according to claim 6 wherein the inert organic solvent is diglyme. 8. The process according to claim 1 wherein the reduction is conducted at temperatures of from about 50"C to about 150-C. 9. The process according to claim 1 wherein the complex is Jbis-(rj 5 -cyclopentadienyl)titanium dichloride. 10. The process according to claim 1 wherein the reducing agent is sodium tetrahydridoborate. 11. The process according to claim 1 wherein the haiogenated hydrocarbon is a polychlorinated aliphatic hydrocarbon. 12. The process according to claim 1 wherein the haiogenated hydrocarbon is a polychlorinated olefinic hydrocarbon.

Inventors: LIU YUMIN, SCHWARTZ JEFFREY, LIU, YUMIN, SCHWARTZ, JEFFREY
Applicants: LIU YUMIN, SCHWARTZ JEFFREY, UNIV PRINCETON, LIU, YUMIN, SCHWARTZ, JEFFREY, THE TRUSTEES OF PRINCETON UNIVERSITY
Application year: 1994
Main classification: C02F1
IPC codes: A62D3, A62D101, B01J31, C02F1, C07B61, C07C17, C07C21, C07C25